The hard encryption keyboard of a bank self-service equipment bears works of inputting and encrypting a bank password of a user, and thus a working key and a master key of the bank are stored in a core processing part of the keyboard. For an unspeakable purpose, some criminals usually jimmy or poke the keyboard to steal the user password and even to decrypt the working key and master key of the bank in order to steal bank information, which threatens the security of information and money of the user and the bank directly.
The existing ATM encryption keyboard includes a keyboard panel and a main control board. A removal detection and protection circuit is provided in a main chip in the main control board, and a plurality of lead pins of the removal detection and protection circuit are led out from the main control board to form removal detection points. Each removal detection point is provided with two disconnected signal contacts which are connected to the removal detection and protection circuit of the main chip via inner wirings of the main control board. Conductive adhesive is provided on a surface, which contacts with the main control board, of the keyboard panel at positions corresponding to the removal detection points of the main control board. When the keyboard is mounted on the mounting panel of the ATM, the keyboard panel presses the conductive adhesive, so that the conductive adhesive contacts with and connects with the disconnected removal detection points on the main control board to form a closed circuit. When the keyboard is being disassembled illegally, the conductive adhesive runs away from the signal contacts to break the circuit, which can be sensed. As a result, the removal detection and protection circuit is triggered to delete sensitive information from the keyboard main chip and to disable relevant functions, thereby preventing the criminal from stealing bank information.
In the prior art, one layer of water-proof silicone rubber is generally provided between the keyboard panel and the main control board in order to enable the encryption keyboard to have a certain water-proof function, and the conductive adhesive is provided between the water-proof silicone rubber and the main control board. This technology has some disadvantages. Since the water-proof silicone rubber is made of elastic material, before disassembling the keyboard the criminal can insert a hard object through the clearance between the conductive adhesive and the panel and thus keep the object to press the conductive adhesive, so as to maintain the continuous connection between the conductive adhesive and the removal detection and protection circuit, and thus the keyboard may be disassembled without being sensed; or the criminal can insert a metal sheet through the clearance between the conductive adhesive and the removal detection points to maintain the continuous connection of the removal detection and protection circuit; or the criminal can fill with conductive glue through the clearance between the conductive adhesive and the removal detection points to maintain the continuous connection of the removal detection and protection circuit. In this way, in the case of being illegally disassembled, the encryption keyboard cannot be self-destructed and the user's password is illegally stolen, even the working key and main key of the bank are decrypted so as to steal the bank information, which threatens the security of information and money of users and bank directly.